Gas lift means



M. P. BURKE GAS LIFT MEANS May 5, 1931.

4 Sheets-Shet 1 Filed March 28. 1927 May 5,

Filed March 2 1927 4 Sheet et 2 M. P. BURKE GAS LIFT MEANS 4 Sheets-Sheet 5 Filed March 28'. 1927 lllfllrllllII/JIL I attorney J y 1931- M. P. BURKE 1,803,837

GAS.LIFT MEANS Filed March 28, 1927 4 Sheets-Sheet 4 gwwntoz J37 9720/2/1 fQ/ZLM/ke Fatented May 5,

UNITED STATES PATEN when T OFFICE MARK P. BURKE, OF LONG BEACH, CALIFORNIA GAS LIFT MEANS Application filed March 28, 1927. Serial No. 178,962.

, well.

Many-forms of gas lifts and methods of operating the same have been heretofore suggested, patented, and, in some cases, used, but these forms of gas lift have for the most part been unsatisfactory, due to the fact that the same have caused the placing upon the well sands, strata or the hke, a pressure,which has a tendency to drive the liquid desired to be pumped from the well back into the sands and strata, and away fromthe well.

It is therefore an object of this invention to provide a means of raising liquids or fluids from a well which is so operated and which is of such construction as to positively prevent the placing-upon the liquids desired to be pumped, or upon the well sands or'strata, pressure which might induce the fluids to flow or recede from the well. Another object of this invention is to pro vide a meansof lifting fluids-from a well by means of gas pressure, which operates to lift the fluid or liquid in slugs from the well.

Another object of this invention is to pro vide a means of lifting liquids from a well, which is of such mode of operation and construction as to permit the liquid in the well to freely flow around the well tubing or the like, even while the gas lift is being operated to raise the liquid in the well.

Another object of this invention is to provide a means of lifting fluids from a well, which is adaptable for use in connection with all wells, regardless of the depth of the well, and regardless of the well pressure which is produced or found in the well.

Another object of this invention is to produce a means of raising liquids from a well,

which includes the operation of a plurality of wells connected in a system and operated in certain alternate timed relation, which may be varied in the case of any particular well,

0 depending upon the Well pressure or the slug of fluid or liquid that is let into the apparatus by the well pressure.

Another object of this invention is to provide a means of lifting liquids from a well, which is of such mode of operation that the gas employed for lifting the liquid from gas lift the well acts upon the liquid in the well to raise the same from the well when the liquid in the well is already'in motion, tendin to rise in the well, and is in position ahead of the gas or air being employed to raise the same from the well.

Other objects and advantages of this invention it is believed will be apparent from the following detailed descriptlon thereof, as illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a diagrammatic view illustrating the manner of connecting a plurality of wells for operation in accordance with the method embodying this invention.

Figure 2 is'a fragmental central sectional view of an air lift apparatus embodying this invention.

Figure 3 is an enlargedfragmental central sectional view of the gas pressure control means embodied in this invention, illustrating the bellows valve as moved to position to ermit the gas pressure previously admitted mto the a paratus to be exhausted to permit the free I ow of theliquid to be pumped from the well into the lifting chamber of the apparatus.

Figure 4 is a similar central sectlonal side elevation taken substantially on the line 44 of Fig. 3.

Figure 5 is a sectional end elevation taken substantially on the line 55 of Fig. 2.

Figure 6 is an enlarged sectional detail view of a control valve embodied in this invention.

Figure 7 is a diagrammatic-view of a m dified form or system embodying the metho of raising liquids from a well in accordance with this invention.

Figure 8 is a fragmental central sectional view of amodified form of gas lift apparatus embodied in this invention.

Figure!) is an end sectional view taken substantially on the line 9-9 of Fi 8.

Figure 10 is an end sectiona view taken substantially on the line 10-1-10 of Fig. 8.

Figure 11 is an enlarged detail sectional view of a control valve as embodied inthe modified form of the apparatus embodying this invention.

Figure 12 is an end section of the control valve illustrated in Fig. 11.

Figure 13 is a front elevation of a control mechanism embodied in this invention for controlling the exhaust and inflow of gas or air into the air lift apparatus embodied in this invention.

Figure 14 is a diagrammatic view of an electrical control mechanism embodied in this invention, adapted for use in operating the valve control means illustrated in Fig. 13.

In accordance with this invention, a plurality of wells, such as indicated at A, B and C, are connected by means of conduits 1, 2 and 3, respectively, with a header 4. The header 4 is connected with a compressor of any suitable or desirable construction, such as indicated at 5, by means of a conduit 6. Mounted in each of the conduits 1, 2 and 3, either at the well or at a central control station, is an automatically operated control valve 7. The control valves 7 are of such construction and are operated so as to intermittently permit the fluid under pressure, such, for example, as gas or air, to pass from the compressor 4 into-the wells A, B or O in a manner as will hereinafter be specifically described.

Means, the construction of which will be hereinafter specifically described, are illustrated at 8 for automatically actuating a motor operatively connected with the control valve 7, so that the control valve 7 of each of the wells A, B and C is operated in timed relation, the fluid under pressure being admitted to the well A while the liquid is ris- 1ng inthe wells B- and G into the air lift chamber, and then being 'cut off so as to permit the fluid or gas admitted to the well to be exhausted therefrom to permit the liquid to fill the fluid lift chamber in the well A. As the wellA is cutoff by actuation of its control valvefi, the control valve of the well B is actuated: to open the same to permit the fluid to be blown into the well B to raise; the fluid therein, and after a predetermined time, the

valve 7 for the well B is actuated to close the same, at which time the control valve 7 for the well C is opened. Thismethod provides a successive actuation'of-the control valves 7 for the wells A, B and C, or for any number of wells that maybe connected in the system,

so that at one time only one well or a group of wells is bein blown to raise the liquid therein, the liquid to be raised in the well, such, for example, as oil, being permitted to rise into the fluid lift chambers of the re-- maining wells while the one well or group of wells is being blown to lift the oil or other liquid to the surface of the ground.

Means are provided for admitting gas or fluid under pressure into the wells A, B or C, I

liquid desired to be pumped from the well to recede or flow from the well, and which means are preferably of the following construction:

The wells preferably include casings 9, which are customarily provided in the case of oil or like wells, and may be of any suitable or desirable construction. The casing 9 is usually provided at its upper end with a casing head, which is diagrammatically illustrated at 10 and through which the well tubing 11 projects. The well tubing 11 is mounted concentrically within the casing 9 and extends downward in the Well to a point below the fluid level in the well, the fluid level in the well being preferably, in relation to the tubing 11, at a point substantially as illustrated at 12. Mounted concentrically Within the tubing 11 and extending downwardly therein is a pipe 13, which may be of any suitable or desirable construction. The pipe 13 extends through the upper closed end of the tubing 11 and extends from the well to any suitable-point of disposal or storage of the liquid being lifted from the well. The tubing from the well is controlled. Secured to the lower end of the housing 18 is a continuation 19 of the tubing 11, which may extend to any suitable or desirable point in the, well.

In order to permit the pipe 13 to be releasably connected with the connecting member 14, the connecting member 14 is proylded at its upper end with a beveled seat 20 1nto which a beveled shoe 21 is adapted to fit. The beveled shoe 21 is secured to the lower end of the pipe 13 so that when the pipe 13 1s lowered into the well until the shoe 21 engages within the beveled seat 20, the weight of the pipe 18 tends to maintain the shoe 21 in position in substantially fluid-tight connection with the connecting member 14. The shoe 21 is secured to the lower section of pipe 13 by any suitable means, such as the threads 22. Formed through the connecting member 14 [is a passage 23 which communicates at its upper end with the interior of the pipe 13 and at its lower end communicates with the interior of a section of pipe 24 which extends downward to a point near the lower end of the chamber 17 Means are provided for controlling the admission of the fluid under pressure into the liquid lift chamber 17 and for exhausting the fluid under pressure from the chamber 17 when the control valve 7 is actuated, which means are preferably of the following construction:

Formed through the connecting member 14 is a port 25, or a plurality of such ports 25 may be provided, depending upon the volume of gas or air which it is desired to introduce into the fluid chamber 17. Formed 15 within the connecting member 14 is a con-' trol valve recess 26. Mounted within the recess 26 is a fluid actuated valve 27 which is adapted to be actuated after the control valve 7 has been actuated to close the conduit 1 to prevent further inflow of gas or air under pressure into the well. The fluid actuated valve 27 is adapted to operate after the fluid under pressure has been cut off from the well at the valve 7 so as to permit the gas previously admitted into the fluid lift chamber 17 to be exhausted therefrom to permit the admission into the chamber 17 of more oil or other liquid from the exterior of the air lift assembly. The fluid actuated valve 27 is preferably of the bellows type, and is set to operate after a predetermined pressurehas been built up within the chamber 26 so as to open the passage 28 formed transversely of the connecting member 14 to permit the fluid under pressure to flow downwardly through the longitudinally extending port 29 into the chamber 17. Formed through the connecting member 14 and communicating at its lower end with the chamber 17 is a port 30, which communicates at its upper end with a transversely extending port 31 which is controlled by a valve actuated by the fluid operated valve 27, the said valve operating to close the port 31 when gas or air under pressure is being admitted into the chamber 17, being actuated by the .fluid actuated valve 27, and operating when the control valve 7 is closed to prevent further admission of gas or oil into the well to open the port 31 and permit the gas previously admitted to the chamber 17 to flow through the ports 30 and 31 into the ort 23 formed through the connecting mem r 14 in advance of the liquid or oil that is being admitted to the chamber 17 by the check valve 32 and by the fluid actuated valve 33 which controls the admission of the oil or liquid to be-raised in the well into the chamber 17.

The fluid actuated valve 27 is preferably of the following construction: The valve 27 is preferably of the bellows type, and is con-' structed of any suitable or desirable material, such as is Well understood in the art, and is connected at its upper end to a cap 34 which has a longitudinally extending. port 35 &

formed therethrough. The-port 35 is provided with a plug 36 at its upper end which is screw-threaded into the extension 37 of the cap 34. In order to determine the pressure at which the fluid actuated valve 27 will be operated, air or gas .under pressure is. forced into the bellows of the fluid actuated valve 27 before the same is positioned within the recess 26, and the plug 36 is screw-threaded into position to maintain the gas under pressure within the bellows, The bellows of the fluid actuated valve 27 are secured at the opposite end to a lower end plate 38 which has an elongated rod extension formed preferably integral therewith, which extends downward into a bore 40 formed in the connecting member 14. Formed in the rod 39 is a circumferential recess 41 which is formed in position to register with the transversely extendin port 28 when the bellows valve is actuatediy the gas under pressure admitted 'to the chamber 26 to open the transverse port 28 and permit the gas to flowthrough the ports 28 and 29 and into the chamber 17. Formed below the circumferential recess 41 and spaced therefrom is a second circumferential recess 42 which provides an exhaust port which is adapted to register with the transversely extending port 31 formed in the connecting member 14 when the rod 39 is actuated by the bellows of the valve after the gas, air or fluid under pressure has been out OK by the control valve 7. The gas or other fluid admitted by the control valve 7 into the chamber 26 acts against the surface 43 of the lower late 28 of the bellows to compress the gas within the bellows to actuate. the rod 39 to open the transverse port 28 when the control valve 7 has been opened.

Means are provided for admitting a definite predetermined quantity or slug of liquid or oil to be pumped from the well into the chamber 17 irrespective of the rock, gas

or well pressure in the well, which means are preferably of the following construction:

The housing 18 encloses a bellows valve substantially of the same construction as the fluid actuated valve 27, which is mounted intormediate the transverse webs 44 and 45 of the housing 18. The housing 18 provides a pressure chamber 46 within which the bellows valve 33 is mounted, and communica tion from the chamber 46 is established through a port 47 formed-through the web 44 and through the axial bore 48 at the top substantially the same construction as the fluid' actuated valve 27 and includes a stem 52, which is slidably mounted within an axial bore 53 formed in the lower web 45 of the housing 18. The stem 52 is provided with a circumferential recess 54 formed in position to establish communication through the transverse port 50 between the ports 49 and 51' when the liquid to be pumped in the chamber 17 has been forced therefrom because of the gas or air pressure admitted to the chamber 17, as heretofore described. The bellows valve 33 operates, when a predeterminedheight of oil or li uid to be raised from the well has been a mitted into the chamber 17 through the ports 49, 50 and 51 by the hydrostatic pressure of this column of oil acting upon the face 55 of the lower plate 56 of the bellows valve 33, to move the valve stem 52 upward and to move the .circumferential recess formed in the valve stem 52 out of position to establish communication through the port 50 between the ports 49 and 51. When the oil or liquid to be lifted from the well has been raised by the gas pressure admitted into {the well so as to relieve the pressure on the face 55 of the bellows valve 33, the bellows 33 expands to again move the circumferential recess 35 into position to establish communication between the ports 49 and 51.

In case for any reason the gas, rock or well pressure of the well falls below the predetermined amount required to raise the liquid to be lifted from the well into the chamber 17 to a predetermined height to close the bellows valve 33, it is preferable that means be provided for preventing the return of the oil or gas that has been admitted into the chamber 17 into the well when the gas pressure is admitted into the well by actuation of the valve 7, which means preferably comprise a ball valve 57 which is seated upon a seat 58 formed in the web 59 of the housing 18 to close the port 48 and prevent the return of the liquid into the well. The ball valve 57 is maintained in position.by the lower end 60 of the tube or pipe 24.

The control valve 7 maybe of any suitable or desirable construction, and as illustrated in Fig. 6 comprises a housing 61 within which a plug 62 of any suitable or desirable construction is mounted. The hou'sing'61 is provided with a port 63 which extends transversely therethrough, and the plug 62 is cut away, as illustrated at 64, so that on rotation of the plug 62 communication is established through the housing 61. The housing 61 is connected at its opposite end with the opposite branches of the conduit 1. The rotation of the plug 62 is accomplished by means which will hereinafter be described.

Referring to Figs. 7 to 12, inclusive, the modified form of gas lift apparatus illustrated therein is preferably of the following construction: As illustrated in Fig. 1, the system embodied in Fig. 7 includes three wells, or any suitable or desired number of wells,']), E and F, which are connected by lustrated at 69.

suitable or desirable source of fluid under pressure, such, for example, as the pum il- The conduits 65, 66 an 67 are connected with the housing 70 of control valve 71. The housing 7 O of the control valve 71 is connected by means of a conduit 72 with an inner concentric pipe 73 which extends downward into the well within the well tubing 74. The well tubing 74 is concentrically mounted within the casing 75, which is simi- 'lar'to the casing 9 and may be of any suitable or desirable construction.

Secured to the lower end of the tubing 74 is a connecting member 76 which is at its opposite end secured to a second section of tubing 77. The tubing 77 is at its lower end secured to a housing 78 similar to the housing 18, which encloses a bellows valve 79 similar in construction to and operating in the same manner as the bellows valve 33.

The pipe 73 is provided with a shoe 80 at its lower end, which fits within a tapered seat 81 formed at the upper end of the connecting member 76, so that the weight of the pipe 73 maintains a substantially fluid-tight connection between the shoe 80 and tapered seat 81. A passage is formed through the shoe 80 for establishing communication between the pipe 73 and ports 82 formed through the connecting member 76. The ports 82 communicate at their lower end with a chamber 83 formed below the connecting member 76 and above the housing 78. The chamber 83 provides the chamber for receiving the liquid or oil to be raised from the well. The connecting member 76 is preferably formed of two sections, one of which sections, 84, rovides the outer housing or connecting mem r, and the other of which, 85, is seated at a tapered seat 86 formed at the lower end of the section 84. A passage 87 is formed in the section 85 and is closed at its upper end, as illustrated at 88. Formed transversely through the section 85 of the connecting member 76, intermediate the ports 82, are passages 89 which communicate on their interior with the passage 87 and on their exterior communicate with a chamber or space 90, formed between the sections 84 and 85. Secured to the lower'end of the section 85 of the connecting member 76 is a pipe 91 which extends downward to a point near the lower end of the chamber 83, formed by the section 77 o the tubing 74. A ball valve 92, similar in construction and for the same purpose as the ball valve 57, is provided.

The housing 71 of the valve 70 is, in the modified form of the invention illustrated in Fig. 7, provided with two spaced passages 93 and 94, which are interrupted by a plug 95 which is fitted within the housing 71 and is provided with a cut away portion 96. The passage 93 provides a passage through which the fluid and gas under pressure is admitted into the well to raise the liquid therein. The conduit is secured to the housing 71 by any suitable or desirable means, as illustrated at 97, and is also secured to the conduit 72 by any suitable or desirable means, as illustrated at 98. The passage 94 formed through the housing 73 provides an exhaust port through which the gas admitted to the well is exhausted when the plug 95 is rotated to position to establish communication through the cut away portion 96 thereof. The passage 96 is in open communication with an exhaust pipe 99 which is secured to the housing 71, as illustrated at 100. The exhaust pipe 99 is secured to the pipe 72 by any suitable or desirable means, as illustrated at 101. The opposite end of the passage 94 may be secured to a pipe 102 which leads to any suitable or desirable point of disposal of the gas which is exhausted from the well when the plug 95 is rotated to close the passage 93 and prevent further admission of gas or fluid under pressure to the well, and is rotated to position to open the passage 94 to permit the gas or fluid under pressure which has been admitted into thewell for the purpose of lifting the liquid or oil from the well from. y

As the construction and operation of the bellows valve 79 and its houslng 78 are substantially the same as the construction and operation of the housing 18 and bellows valve 33, the same numerals have been afiixed to the separate parts of the bellows valve 79 and housing 78 as are employed in designatto be exhausted thereing the construction of the'valve 33 and housing 18, with the sufiix a added to each number.

Means are provided for actuating either the control valve 7 or the control valve 70, which means may be of any preferred construction, and are herein illustrated as comprising a shaft 103 which is secured to the plugs 62 or 95 of the valves 7 or 7 0, and is also secured to a worm; gear 104 which is adapted to'mesh with a worm 105. The worm 105 is secured to a shaft 106, which is driven by an electric or other suitable motor 107. Secured to the face of the worm gear 104 is a lug 108, which is adapted to engage either the trip contact 109 or the trip contact 110 to con ilpgete an electric circuit to the motor 107. e contacts 109 and 110 may be of the same construction, and include a slide 111 which is slidably mounted in position on a standard 112, and are electrically connected with electrical conduits 113 or 114. The

slides 111 are rovided with fingers 115',the continuation 0 which is formed asa spring finger 116, which is adapted to be engaged by the lug 108 mounted upon the periphery of the worm gear 104. The engagement of the lug 108 with the spring finger 109 causes the contact point 107 to be moved either to or from the contacting position with a second contact finger 118 which is electrically connected with the electrical conduit 119 or the electrical conduit 120. For each well one of the foregoing described control mechanisms is provided. The electrical leads 114 and 120, and 113 and 119 are connected with the electric motor 107 so that on contacting of, for example, the contact 117 with the contact 118, which connects the leads 113 and 119, the electric motor 107 is caused to travel in one direction .to rotate the worm gear 104 in a like relation to rotate either the plug 62 of the valve 7 or the plug 95 of the valve from the open position, as illustrated Figs. 6 and 11, to the closed position, preventing the inflow of gas into the well, and in the case of the control valve 70, as illustrated in Fig. 7, to rotate the plug 95 from the position illustrated in Fig. 11 to the position to establish communication between the pipes 99 and 102 through the cut away portion 96 and plug 95. On contacting of the opposite pair of leads 114 and 120, the motor 107 1s caused to travel in a reverse direction to reverse the direction of rotation of the plugs 62and 95 above described.

Means are provided for establishing proper electrical connection between the separate control units in a certain predetermined relation, which means are preferably of the following construction:

Mounted within the housing 121 on a shaft 122 is a contact drum 123, which carries on its periphery at spaced and predetermined intervals contacts 124, 125, 126, 127, 128, 129, 130 and 131. The drum shaft 122, and hence the drum 123, are driven by means of a worm drive 132, which in turn is drlven from a second worm drive 133 to obtaln a speed reduction from an electric motor 134 wh ch drives the worm 133 through a pair of gears 135 and 136, respectively. The gear 135 is secured directly to the shaft 137 of the motor 134, and the gear 136 is secured directly to the shaft 138 of the worm dr ve 133 so that .the two gears 135 and 136 may be changed as desired, to change the speed of drlve of the drum 123 when it is either deslred to 1ncrease or decrease the intervals of time withm which the' gas is blown into the well.

The operation of the electrical control means illustrated in Fig. 14 isthe drum 123, being rotated through means heretofore dcscribed, causes the contacts 130 and 131 to engage stationary ,contacts 139, 140, 141 and 142. The contact 139 is connected by means of-an electrical conduit 143 with the lead 120 of the control mechanism illustrated m'Fig. 13 for the well-A, the contact 140 15 connected with the lead 114 of the well A, the contact 141 is connected with the lead 113 of the control mechanism for the well B, and the contact 142 is connected with the lead 119i-of the control mechanism of the well B, so that as the contact 130 engages the contacts 139 and 140, the control mechanism of the well A is caused to operate to rotate the control valve thereof to arrest further inflow of gas into the well A, and at the same time the control mechanism for the well B is actuated by the contacting of the contact 131 with the contacts 141 and 142 to actuate the control mechanism for the well B, to open the control valve thereof to allow the fluid under pressure to flow into the well. The contact 124 is connected with the control mechanism of the well B in the same manner as the contact 130 is connected with the control mechanism for the well A. In a like manner, the contacts 125, 126, 127, 128, and 129 are connected with the control mechanisms of the wells C, C, D, D, and A, respectively, so that the wells are connected in series in such a manner as to cause a progressive opening of the control valves so that only one control valve or one set of control valves, depending upon the number of wells included in the system, is open at a time to receive fluid under pressure. The positioning of the contacts in the drum 123 may be regulated in such a manner as to allow any certain well or any group of wells to receive gas under pressure for a different period of time than the other wells of the series, and it is also possible, by properly connecting up the contacts on the drum 123, to permit gas to flow into any particular well in which the gas or rock pressure in the well is large, to'be flowed at more frequent intervals than the remaining wells. Thus, a well which ordinarily would produce four or five hundred barrels of oil a day may be flowed twice as often as a well which ordinarily would produce only two hundred barrels per ,day.

Having fully described my invention, it is to be understood that I do not 'wish to be limited to the details herein set forth, which may obviously be varied without departing from the spirit of my invention as defined by the appended claims.

I claim 1. In a device of the class described, the comblnation of a pair of concentrically mounted pipes, a connecting member secured to the lower ends of said concentrically mounted pipes, one of said pipes providing an inlet gas fluid conduit and the other of said pipes providing an outlet fluid conduit, a fluid pressure operated valve mounted in the said connecting member and adapted to be actuated by the pressure of the fluid admitted through the fluid inlet conduit, a pipe secured to the lower end of the connecting member and providing a gas lift chamber, and means actuated by the fluid pressure in the gas lift chamber for exhausting the gas under pressure from the gas" lift chamber through the fluid outlet conduit.

2. A gas lift for raising liquids from a well having a fluid lift chamber, positive means for admitting a predetermined quantity of a predetermined pressure is established in the lift chamber, and means for exhausting the gas from the lift chamber through the outlet pipe with the liquid under pressure admitted to the lift chamber to force the liquid from the well as a slug;

3. An apparatus of the class described including a pair of concentrically mounted pipes, one of which pipes provides a fluid inlet pipe and the other of which provides a fluid outlet pipe, means secured to the lower end of said concentrically mounted pipes in communication therewith and providing a gas lift chamber, means for admitting gas under pressure through the fluid inlet pipe to the gas chamber, means for arresting the. flow of fluid under pressure to the gas lift chamber, and means for exhausting the gas with the fluid being lifted from the lift chamber through the fluid outlet pipe.

4. A gas lift including a pair of concentrically mounted pipes, one of which pipes provides a fluid inlet conduit and the other of which pipes provides a fluid outlet conduit, means supported at the end of said concentrically mounted pipes and providing a gas lift chamber, valve means for admitting the liquid to be lifted into the gas lift chamber, means for conveying a pressure fluid through the fluid inlet conduit to the lift chamber to force the liquid under pressure from the lift chamber, and means operable for exhausting the gas from the fluid 11ft chamber through the fluid outlet conduit with the liquid being lifted.

5. A gas lift having a lift chamber, means for admitting a predetermined quantity of liquid from the well into the lift chamber irrespective of the pressure in the well, means for admitting gas under pressure into the lift chamber, an outlet pipe connected with the lift chamber, means for arresting the flow of gas under pressure to the lift chamber after a predetermined pressure is established in a predetermined pressure is established in the lift chamber, and a check valve controlling the liquid inlet to the lift chamber and operable to prevent back-flow of liquid through the fluid lift chamber inlet when gas under pressure is admitted into the lift chamber, and means additional tosaid check valve for admitting a definite amount of liquid to said lift chamber. a 4

7. A gas lift providing a fluid lift chamber, valve means mounted in the liquid inlet to the fluid lift chamber,.means controlled by the column of liquid in the fluid lift chamber for closing said valve means irrespective of the pressure in the well, means for admitting gas under pressure into the lift chamber, a check valve controlling the admission of liquid into the fluid lift chamber above the first said valve means and operable to prevent back-flow of liquid from the fluid lift chamber through the liquid inlet, and means for arresting the flow of gas under pressure to the lift chamber after a predetermined pressure is established in the lift chamber.

8. A gas lift having a fluid lift chamber, positive means for admitting a predetermined quantity of liquid from the well into the lift chamber irrespective of the pressure in the well, means controlled-by the pressure of the fluid in the lift chamber for actuating the latter said means to close the same after a predetermined column of liquidhas been admitted to the lift chamber, means for admitting gas under pressure into the lift chamber, an outlet pipe connected with the lift chamber, and means controlled by the fluid pressure in the lift chamber for arresting the flow of gas under pressure to the lift chamr. 9. A gas lift providing a fluid lift chamber,

valve means for admitting a predetermined quantity of liquid from a well into the lift chamber, fluid pressure extensible means operably connected with said valve means for actuating the same, means for admitting gas under pressure into the chamber, an outlet pipe connected with the lift chamber and said concentrically mounted pipes to pass through the fluid inlet passage formed through the connecting member to force the said liquid from the gas lift chamber through the other of said concentrically mounted 1 es. 7 p 1siigned at Los Angeles, Calif, this 16 day of ar ch, 1927. MARK P. BURKE.

extending to the surface of a well, means for combination of a pair of concentrically mounted pipes, a connecting member mounted at the ends of said pipes, a fluid inletpassage formed throu h the said connecting member and a flui outlet passage formed through said connecting member, a pipe secured to the end of the connecting member and providing a fluid lift chamber, a fluid ressure actuated valve mounted in the fluid Q mlet conduit formed in the connecting memher and operable irrespective of the pressure 

